Sex question!!

AWKARD QUESTION!!

Our sex is really great, however he recently shared with me tonight when doing certain positions whether it’s missionary, legs on shoulder or me on my back at the edge of the bed he tends to finish really fast because he said that I tend to get super tight around his tip toward my cervix area (I don’t even feel myself contracting nor am I at the brink of an orgasm to have this happen without even realizing) Is there a way for my end to avoid this so he lasts longer/less tight?? He is a bit above average girth wise. I asked if this is normal for a guys end to experience when having sex with women and he said I’m the only one he’s experienced this with. Any advice? Kegel exercises I feel aren’t what I need apparently since I’m already tightly gripped down there already lol.